Natural Radioactivity of the Crystalline Basement Rocks of the Peloritani Mountains (North-Eastern Sicily, Italy): Measurements and Radiological Hazard

Crystalline rocks can produce dangerous radiation levels on the basis of their content in radioisotopes. Here, we report radiological data from 10 metamorphic and igneous rock samples collected from the crystalline basement of the Peloritani Mountains (southern Italy). In order to evaluate the radiological properties of these rocks, the gamma radiation and the radon emanation have been measured. Moreover, since some of these rocks are employed as building materials, we assess the potential hazard for population connected to their use. Gamma spectroscopy was used to measure the 226Ra, 232Th and 40K activity concentration, whereas the radon emanation was investigated by using a RAD 7 detector. The results show 226Ra, 232Th and 40K activity concentration values ranging from (17 ± 4) to (56 ± 8) Bq kg-1, (14 ± 3) to (77 ± 14) Bq kg-1 and (167 ± 84) to (1760 ± 242) Bq kg-1, respectively. Values of the annual effective dose equivalent outdoor range from 0.035 to 0.152 mSv y-1, whereas the gamma index is in the range of 0.22-0.98. The 222Rn emanation coefficient and the 222Rn surface exhalation rate vary from (0.63 ± 0.3) to (8.27 ± 1.6)% and from (0.12 ± 0.03) to (2.75 ± 0.17) Bq m-2 h-1, respectively. The indoor radon derived from the building use of these rocks induces an approximate contribution to the annual effective dose ranging from 8 to 176 μSv y-1. All the obtained results suggest that the crystalline rocks from the Peloritani Mountains are not harmful for the residential population, even though they induce annual effective doses due to terrestrial gamma radiation above the worldwide average values. Moreover, their use as building materials does not produce significant health hazards connected to the indoor radon exposure.

Pure optical nano-writing on light- switchable spiropyrans/merocyanine thin film

We report optical writing at the nanometer scale of spin coated PMMA-spiropyran films. By using a near-field optical microscope, pure optical nano-writing with a resolution of 160 nm and writing speed of 0.4 µm/s was achieved. Simultaneous topographic and optical writing was also obtained by simply coupling to the near-field few more mW of laser power. Due to the fast optical response of the spiropyran molecule, nano-lithography on PMMA-spyropyran thin films appears to be very attractive for future photonics applications.

Rhinomanometric and olfactometric variations throughout the menstrual cycle

A prospective study was performed to evaluate the rhinomanometric values and the changes in the olfactory threshold that occur in women throughout the menstrual cycle. The subjects were 60 healthy volunteer premenopausal women 18 to 40 years of age. We performed rhinomanometric and olfactometric measurements during the follicular, periovular, and luteal phases of the menstrual cycle. Rhinomanometry showed a higher (not statistically significant) airflow during the periovular phase than during the follicular and luteal phases. Olfactometry showed a higher sensitivity during the follicular phase (p < .05) and the periovular phase (p < .001) than during the luteal phase. We conclude that airflow and transnasal pressure during spontaneous respiration, as well as the olfactory threshold to odors, seem to depend on the variations of the ovarian steroids that occur during the menstrual cycle.

One hundred and twenty-seven cases of acute subdural haematoma operated on. Correlation between CT scan findings and outcome

Traumatic acute subdural haematoma is one of the most lethal of all head injuries: the mortality rate is reported to be between 50 and 90%. We reviewed the clinical records of 1688 head injured patients admitted to the Department of Neurosurgery at C.T.O. hospital between 1982 and 1992. In 127 cases (7,5%) CTscan on admission showed acute subdural haematoma requiring surgery because the midline shift was greater than 5 mm. The overall mortality rate was 57% and 23% had functional recovery. The following variables were assessed with regard to morbidity and mortality: mechanism of injury, age, neurological presentation, time delay from injury to intervention, CTscan finding on admission. GCS and CTscan findings were found to be the most important prognostic variable. Timing of operative intervention for clot removal with regard to outcome was not statistically significant. But no conclusions regarding the importance of early haematoma evacuation can be drawn from such an oversimplifying statement, because it does not take into account factors like rapidity of haematoma development and related brain decompensation as well as additional direct brain lesions. The results of this study suggest that the extent of primary brain injury underlying the subdural haematoma is the most important factor affecting outcome.